Oscar, 20, has been attracting the attention of Europe's major clubs after some impressive performances for Brazil and has become the Blues' latest recruit - alongside Eden Hazard and Marko Marin - as they look to assert more dominance in the Premier League this season.

A statement on the Chelsea website read: "Chelsea Football Club is delighted to announce the signing of Oscar."

The midfielder, full name Oscar dos Santos Emboaba Junior, is part of Brazil's squad for London 2012 and played in the 2-0 warm-up
victory over Team GB last Friday.

The move marks a stunning rise in his young career as his senior Brazil debut arrived only in September last year when he came on as a substitute
in a 0-0 draw with Argentina, and he has scored once in six caps.